Fluid actuated impact device



y 5, 1965 D. A. u|-|| 3,185,223 I FLUID ACTUATED IMPACT DEVICE Filed July 6, 1962 2 Sheets-Sheet 1' FIG. 3

F/GZZ 28 r59 48 27 44 4/ G L i 65 50 I 2f 45 56 l l c 60 43 z 54 i 24 I i I 76 Y 52 66 22 v Q 62 1 67 i 4 F 4 I i' 55 INVENTOR. I. I DONALD A. HL

mi dzzz ATTORNEYS May 25, 1965 v D. A. u|-|| 3,185,223

FLUID AGTUATED IMPACT DEVICE INVENTOR. DONALD A. UHL

A T TOR/VE Y8 United States Patent This invention relates to fluid actuated impact devices for drilling, hammering, and the like.

In general, the apparatus of the present invention comprises a housing means forming chamber and including an inlet port for receiving a flow of non-compressible fluid, such as water at city main pressure, or hydraulic fluid from a pump in closed circuit applications.

Resiliency for the system is provided by a resilient moveable wall which may be in the form of a piston one side of which is exposed to said chamber, said piston being constantly urged downwardly by resilient means such as a spring. This piston and spring assembly further functions to accelerate scavenging of fluid from the device whereby the impact force is increased.

The lower end of the housing means slideably carries a piston valve and rod assembly on the upper end of which is provided a slideably mounted piston valve element that is exposed to pressurized fluid in said chamber to cause reciprocation of the device and which also functions to open and close outlet ports from the chamber upon reciprocation of the rod means.

Hammering or drilling is accomplished at the lower end of the above mentioned rod means which carries an anvil portion located below a hammer portion mounted on the lower end of the housing means.

When the previously mentioned inlet port is connected to a source of non-compressible fluid the chamber is pressurized producing a force on the previously mentioned piston valve and rod assembly whereby the housing means is lifted to a position wherein the valve means rapidly dumps fluid from within the chamber.

The housing means, which provides the weight for the impact blow, next descends rapidly and the hammer portion on the bottom thereof imparts a blow to the anvil portion formed by lower end of the piston valve and rod assembly. This action shifts the rod assembly upwardly and closes the previously mentioned outlet ports whereby the chamber is again pressurized to repeat the impact cycle.

It is therefore an object of the present invention to provide a novel impact device that produces reciprocating hammer blow action when charged with a non-compressible fluid.

It is another object of the present invention toprovide a device of the type described that incorporates a spring pressed resilient wall that accelerates scavenging of fluid rom the device and thereby increases impact action.

It is another object of the present invention to provide an apparatus of the type described that incorporates a slideably mounted piston valve and rod assembly that performs multiple functions to provide means for rais ing the housing means to provide kinetic energy from a falling weight, flow control valve means, and an anvil portion for receiving the impact blows generated by the device.

It is another object of the present invention to provide a device of the type described that utilizes a diiferential in inlet and outlet port area to provide a time lag period in each cycle that accomplishes draining and filling of the pressure chamber without the need for timed inlet valving.

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawings where- 3,185,223 Patented May 25, 1965 "ice in a preferred form of embodiment of the invention is clearly shown.

In the drawings:

FIG. 1 is a side elevational view of an impact device constructed in accordance with the present invention;

FIG. 2 is a side sectional view of the device of FIG. 1, the section being taken along a vertical plane through the longitudinal centerline of the device;

FIG. 3 and FIG. 4 are partial side sectional views of the top portion of the device of the preceding figures;

FIGS. 5, 6 and 7 are partial side sectional views of the bottom portion of the device of the preceding figures; and

FIG. 8 is a top sectional view of a piston valve apparatus comprising a portion of the device of the preceding figures, the section being taken along the line 88 of FIG. 5.

Referring in detail to the drawings, FIGS. 1 and 2 illustrate an impact device constructed in accordance withthe present invention that includes housing means 20 comprising an intermediate housing portion 22 formingan inner chamber 24, an upper spring housing 31, and a lower casing portion 46.

Chamber 24 receives pressurized fluid via line 12, a throttle valve 19 and an inlet port 26.

As is best seen in FIGS. 2, 3 and 4, spring housing 31 slideably carries a piston 28 that includes resilient seals 27 engaging the inner wall surface of the spring housing.

Piston 28 is constantly urged downwardly by a compression spring 30 interposed between the top of the piston and a spring mounting plate 32, the tension on said spring being adjustable by actuating a stud 34 disposed in a threaded hole cap 36, the latter being screwed into spring housing 31 at threads 38.

A retainer ring 4% serves to retain piston 28 in spring housing 31, the latter being joined to casing portion 20 by a coupling 42 at the threaded junctions 41 and 43.

Reference is next made to FIGS. 5 and 8 which illustrate the valve and impact mechanism mounted on the lower end of casing means. 20. It will be noted that lower casing portion 46 carries a sleeve means 66 that is rigidly and removably mounted at its upper end to the lower casing portion 46 at a threaded junction 45, said sleeve means including a plurality of radially outwardly and downwardly extending discharge passages 58, FIGS. 7 and 8.

A piston valve and rod assembly 52 is slideably mounted in a first valve portion, sleeve ss, and includes a second valve portion, piston valve element 56, that normally closes discharge passages 58. Piston valve element 56 includes a top surface 59 exposed to the pressurized fluid in chamber 24 and a lower surface 6 1 exposed to the interior of a chamber 66, said element being slideably mounted in an inner'cylindrical' wall of sleeve means 66. The piston valve element may be provided with grooves 65 to increase the lubricating and sealing effect.

With continued reference to FIGS. 5 and 8, piston valve and rod assembly 52 includes rod portions 54 and 55 having confronting ends at a junction 57, said rod portions being slideably carried in a bore extended longitudinally through sleeve means ss. An impact tool such as the drill bit indicated generally at 68, or a hammer element, is mounted on the lower end of rod portion 55 which can be removed as an assembly by screwing threaded pin 64 out of slot 62. It will be noted that the top surface of the tool forms an anvil surface for receiving impact blows from a lower hammer surface 86 on the bottom of the housing means.

In operation of the apparatus, when chamber 24 fills with a non-compressible fluid, piston means 28 yields upwardly, compressing spring 30, until sufiicient force is exerted on top surface 59 of piston valve element 56 to ing intake port 26 and commencing to compress piston 23 a and apply force to top surface 59 of piston valve element 56.

When the housing means 20 and sleeve 66 are raised sufiiciently to open outlet ports 58, fluid is dumped from the chamber causing the housing means and attached components rapidly to descend for another impact blow. When valve means 56-66 opens, compressed spring 30 accelerates dumping of fluid out through passages 58 and 7 thereby increasing impact forces. 7

Since the combined area of the outlet ports is much greater than the area of inlet port 26 the chamber 24 can substantially drain itself even though no timed valving is provided at inlet port 26.

Throttle valve 10 is used to vary the volumetric flow delivery which serves to vary the cyclic rate or speed of the machine.

It should be pointed out that if closed circuit operation is desired, utilizing hydraulic fluid, then the bottom of annular passage 70 is sealed and drained back to tank, a pump being used to redeliver the fluid from tank to chamber 24. a e

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

' I claim: I

V 1. An impact device comprising, in combination, housing means including inner cylindrical Wall means forming a chamber provided with an inlet port in the upper portion of said housing means, outlet port means of larger area than said inlet port, a first valve portion at said outlet port, and a hammer portion; means forming a resilient wall exposed to fluid pressure in said chamber; a piston valve and rod assembly slideably mounted for axial movement in the lower portion of said housing means and including an upper end forming a second valve portion cooperating with said first valve portion of said housing means and an anvil portion disposed below said hammer portion for receiving impacttherefrom upon reciprocation of said housing means relative to said piston valve and rod assembly, the top surface of said upper end of said piston valve and rod assembly being exposed to fluid pressure in said chamber.

2. The impact device defined in claim 1 wherein said piston valve and rod assembly includes coaxially aligned rod portions disposed in end to end relationship.

3. The impact device defined in claim 1 wherein said piston valve and rod assembly includes coaxially aligned rod portions disposed in end to end' relationship; a longitudinal slot in one of said rod portions; and a pin mounted on said housing means and extended into said slot.

4. The impact device defined in claim 1 wherein said resilient wall is formed by an upper piston mounted for reciprocating movement in said cylindrical wall means; and resilient means operative between said upper piston and the upper portion of said housing means for urging said piston downwardly.

5. An impact device comprising, in combination, housing means including inner cylindrical Wall means forming a chamber provided with an inlet port, outlet port means of larger area than said inlet port, sleeve means forming a first valve portion mounted in the lower portion of said housing means and including an upper bore of greater diameter, a lower bore of lesser diameter, and a plurality of outlet ports in the wall of said sleeve means at said bore of larger diameter and a hammer portion; means forming a resilient wall exposed to fluid pressure in said chamber;

* and a hammer portion; a piston valve and rod assembly including a shank portion slideably mounted in said bore of lesser diameter, a piston valve forming a second valve portion, slidea-bly mounted in said bore of larger diameter cooperating with said first valve portion for opening and closing said outlet passage, and a lower anvil portion below said hammer portion of said housing means, said piston valve including an upper surface exposed to fluid pressure in said chamber.

6. The impact device defined in claim 5 wherein said I piston valve and rod assembly includes coaxially aligned rod portions disposed in end to end relationship.

7. The impact device defined in claim 5 wherein said piston valve and rod assembly includes coaxially aligned rod portions disposed in end to end relationship; a longitudinal slot in one of said rod portions; and a pin mounted on said housing means and extended into said slot.

8. The impact device defined in claim 5 wherein said resilient wall is formed by an upper piston mounted for References Cited by the Examiner UNITED STATES PATENTS 4,112,498 10/14 Van ES 17373 2,661,928 12/52 Topanelian 17373 3,064,629 11/62 Story 9l-50 3,065,805 11/62 Martini 17-5-296 FOREIGN PATENTS BROUGHTON G. DURHAM, Primary Examiner.

KARL I ALBRECHT, Examiner.

3 39 Norway. 

1. AN IMPACT DEVICE COMPRISING, IN COMBINATION, HOUSING MEANS INCLUDING INNER CYLINDRICAL WALL MEANS FORMING A CHAMBER PROVIDED WITH AN INLET PORT IN THE UPPER PORTION OF SAID HOUSING MEANS, OUTLET PORT MEANS OF LARGER AREA THAN SAID INLET PORT, A FIRST VALVE PORTION AT SAID OUTLET PORT, AND A HAMMER PORTION; MEANS FORMING A RESILIENT WALL EXPOSED TO FLUID PRESSURE IN SAID CHAMBER; A PISTON VALVE AND ROD ASSEMBLY SLIDEABLY MOUNTED FOR AXIAL MOVEMENT IN THE LOWER PORTION OF SAID HOUSING MEANS AND INCLUDING AN UPPER END FORMING A SECOND VALVE PORTION COOPERATING WITH SAID FIRST VALVE PORTION OF SAID HOUSING MEANS AND AN ANVIL PORTION DISPOSED BELOW SAID HAMMER PORTION RECEIVING IMPACT THEREFROM UPON RECIPROCATION OF SAID HOUSING MEANS RELATIVE TO SAID PISTON VALVE AND ROD ASSEMBLY, THE TOP SURFACE TO SAID UPPER END OF SAID PISTON VALVE AND ROD ASSEMBLY BEING EXPOSED TO FLUID PRESSURE IN SAID CHAMBER. 